Audio devices, such as mobile/cellular telephones, in which users need to hear their own voice during use, are increasing in prevalence. Audio of a user's own voice can be injected into a speaker output being provided to a user. Such audio can be referred to as a sidetone. Sidetones are presented such that the user's voice is heard by the user in the headphones or other speaker as if the speaker and housing were not covering the ear. For example, due to the obstruction provided by the speaker and housing, one or both ears may be partially or totally blocked, which can result in distortion and attenuation of the user's voice in the ambient acoustic environment. These effects are usually termed occlusion effects because they can result from occlusion of an ear, such as by a headphone, earphone, earbud, and the like. Sidetones have been used to at least partially remedy the occlusion problem. However, conventional sidetones do not always provide a natural sound, especially under changing conditions, such as with changes in the speaker type or position or changes in the environment.
To illustrate the current state of the art, FIG. 1 provides an example schematic block diagram illustrating a conventional sidetone generation system according to the prior art. One drawback of the system of FIG. 1 is that the sidetone generation path is fixed. Thus, the generation of sidetones cannot be adapted to have different characteristics for different applications
Shortcomings mentioned here are only representative and are included simply to highlight that a need exists for improved electrical components, particularly for sidetone generation systems employed in personal audio devices, such as mobile phones. Embodiments described herein address certain shortcomings but not necessarily each and every one described here or known in the art.